Nitrogen-doped interconnected carbon nanosheets from pomelo mesocarps for high performance supercapacitors

Here, we report a novel type of nitrogen-doped porous interconnected carbon nanosheets derived from an easily gained and green plant-waste (pomelo mesocarps) by simultaneous activation, carbonization and nitrogen-doped processes using CaCl2 as activating agent and urea as nitrogen source. The nitrogen doped pomelo mesocarps-based nanosheet carbon (N-PMNC) displays an interconnected sheet-like morphology, a high specific surface area (974.6 m(2) g (1)), a porous architecture and a high nitrogen doping content (9.12 wt%). The N-PMNC based supercapacitor exhibited superior electrochemical performance with high specific capacitance of 245 F g (1) at 0.5 Ag (1) and excellent rate capability (72% capacitance retention ratio even at 20 Ag (1)) in 2 mol L (1) KOH electrolyte. Furthermore, N-PMNC based symmetric supercapacitor possesses high specific energy of 14.7 Wh kg (1) at a power density of 90 W kg (1) operated in the wide voltage range of 1.8 V in aqueous neutral Na2SO4 electrolyte, and shows outstanding cyclic stability. (C) 2015 Elsevier Ltd. All rights reserved.